Research should not be influenced by politics
I think you’re probably right. My relationship with academia is shallower than yours. I served on a Board of Governors. I heard a great deal anecdotally from faculty about intended assaults on academic freedom. I never heard anything from the alleged assaulters. Yet I saw frequent evidence of what I perceived to be self-serving and overly protective conduct by both faculty and administration. So, it’s a question of degree with academic freedom being acknowledged as the more important value. If , as you suggest, academic freedom is under constant assault then tenure is justified but if the alleged attacks on academic freedom are mainly fair comment or legitimate skepticism and, at the same time there is deteriorating rigour in peer assessment processes perhaps the question tenure should be reviewed.
You articulately describe the arguments for tenure with which I agree. But I’m skeptical about the checks within the system on the group dynamics of cronyism as well as the separation between the assessment function and the budgeting function. The social benefit of universities are both research and teaching. Each requires different skills and considerable energy. Peer assessment can make too many allowances because the the reviewer will become the reviewed and the system soon will, by the workings of human nature become less and less rigorous. Thanks for raising this important subject.
So just to be clear, the current version not only "grandfathers" in faculty that have tenure now but allows for the granting of tenure to people not currently in tenure position by a group of peers? If so, that is good news.